kernel/arch/riscv/include/asm/fixmap.h, branch linux-rolling-stable

riscv: Move early dtb mapping into the fixmap region

2023-04-30T23:29:23Z

commit ef69d2559fe91f23d27a3d6fd640b5641787d22e upstream. riscv establishes 2 virtual mappings: - early_pg_dir maps the kernel which allows to discover the system memory - swapper_pg_dir installs the final mapping (linear mapping included) We used to map the dtb in early_pg_dir using DTB_EARLY_BASE_VA, and this mapping was not carried over in swapper_pg_dir. It happens that early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is setup otherwise we could allocate reserved memory defined in the dtb. And this function initializes reserved_mem variable with addresses that lie in the early_pg_dir dtb mapping: when those addresses are reused with swapper_pg_dir, this mapping does not exist and then we trap. The previous "fix" was incorrect as early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is set up otherwise we could allocate in reserved memory defined in the dtb. So move the dtb mapping in the fixmap region which is established in early_pg_dir and handed over to swapper_pg_dir. Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob") Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap") Fixes: 50e63dd8ed92 ("riscv: fix reserved memory setup") Reported-by: Conor Dooley Link: https://lore.kernel.org/all/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/ Signed-off-by: Alexandre Ghiti Reviewed-by: Conor Dooley Tested-by: Conor Dooley Link: https://lore.kernel.org/r/20230329081932.79831-2-alexghiti@rivosinc.com Cc: stable@vger.kernel.org # 6.2.x Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman

riscv: remove FIXMAP_PAGE_IO and fall back to its default value

2022-05-12T04:36:33Z

If not defined in the arch, FIXMAP_PAGE_IO defaults to PAGE_KERNEL_IO, which we defined when adding the svpbmt implementation. So drop the FIXMAP_PAGE_IO riscv define. Signed-off-by: Heiko Stuebner Reviewed-by: Christoph Hellwig Reviewed-by: Philipp Tomsich Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/20220511192921.2223629-11-heiko@sntech.de Signed-off-by: Palmer Dabbelt

riscv: mm: Prepare pt_ops helper functions for sv57

2022-02-15T00:32:42Z

This patch prepare some pt_ops helper functions which will be used in creating sv57 mappings during boot time. Signed-off-by: Qinglin Pan Signed-off-by: Palmer Dabbelt

riscv: Implement sv48 support

2022-01-20T01:54:09Z

By adding a new 4th level of page table, give the possibility to 64bit kernel to address 2^48 bytes of virtual address: in practice, that offers 128TB of virtual address space to userspace and allows up to 64TB of physical memory. If the underlying hardware does not support sv48, we will automatically fallback to a standard 3-level page table by folding the new PUD level into PGDIR level. In order to detect HW capabilities at runtime, we use SATP feature that ignores writes with an unsupported mode. Signed-off-by: Alexandre Ghiti Signed-off-by: Palmer Dabbelt

RISC-V: Add early ioremap support

2020-10-02T21:31:03Z

UEFI uses early IO or memory mappings for runtime services before normal ioremap() is usable. Add the necessary fixmap bindings and pmd mappings for generic ioremap support to work. Signed-off-by: Atish Patra Reviewed-by: Anup Patel Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt

RISC-V: Move DT mapping outof fixmap

2020-10-02T21:30:57Z

Currently, RISC-V reserves 1MB of fixmap memory for device tree. However, it maps only single PMD (2MB) space for fixmap which leaves only < 1MB space left for other kernel features such as early ioremap which requires fixmap as well. The fixmap size can be increased by another 2MB but it brings additional complexity and changes the virtual memory layout as well. If we require some additional feature requiring fixmap again, it has to be moved again. Technically, DT doesn't need a fixmap as the memory occupied by the DT is only used during boot. That's why, We map device tree in early page table using two consecutive PGD mappings at lower addresses (< PAGE_OFFSET). This frees lot of space in fixmap and also makes maximum supported device tree size supported as PGDIR_SIZE. Thus, init memory section can be used for the same purpose as well. This simplifies fixmap implementation. Signed-off-by: Anup Patel Signed-off-by: Atish Patra Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt

mm: reorder includes after introduction of linux/pgtable.h

2020-06-09T16:39:13Z

The replacement of with made the include of the latter in the middle of asm includes. Fix this up with the aid of the below script and manual adjustments here and there. import sys import re if len(sys.argv) is not 3: print "USAGE: %s

" % (sys.argv[0]) sys.exit(1) hdr_to_move="#include " % sys.argv[2] moved = False in_hdrs = False with open(sys.argv[1], "r") as f: lines = f.readlines() for _line in lines: line = _line.rstrip(' ') if line == hdr_to_move: continue if line.startswith("#include Signed-off-by: Andrew Morton Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Cain Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Ley Foon Tan Cc: Mark Salter Cc: Matthew Wilcox Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Tony Luck Cc: Vincent Chen Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org Signed-off-by: Linus Torvalds

mm: introduce include/linux/pgtable.h

2020-06-09T16:39:13Z

The include/linux/pgtable.h is going to be the home of generic page table manipulation functions. Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and make the latter include asm/pgtable.h. Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Cain Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Ley Foon Tan Cc: Mark Salter Cc: Matthew Wilcox Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Tony Luck Cc: Vincent Chen Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org Signed-off-by: Linus Torvalds

riscv: introduce interfaces to patch kernel code

2020-03-26T16:24:52Z

On strict kernel memory permission, we couldn't patch code without writable permission. Preserve two holes in fixmap area, so we can map the kernel code temporarily to fixmap area, then patch the instructions. We need two pages here because we support the compressed instruction, so the instruction might be align to 2 bytes. When patching the 32-bit length instruction which is 2 bytes alignment, it will across two pages. Introduce two interfaces to patch kernel code: riscv_patch_text_nosync: - patch code without synchronization, it's caller's responsibility to synchronize all CPUs if needed. riscv_patch_text: - patch code and always synchronize with stop_machine() Signed-off-by: Zong Li Signed-off-by: Palmer Dabbelt

riscv: add nommu support

2019-11-17T23:17:39Z

The kernel runs in M-mode without using page tables, and thus can't run bare metal without help from additional firmware. Most of the patch is just stubbing out code not needed without page tables, but there is an interesting detail in the signals implementation: - The normal RISC-V syscall ABI only implements rt_sigreturn as VDSO entry point, but the ELF VDSO is not supported for nommu Linux. We instead copy the code to call the syscall onto the stack. In addition to enabling the nommu code a new defconfig for a small kernel image that can run in nommu mode on qemu is also provided, to run a kernel in qemu you can use the following command line: qemu-system-riscv64 -smp 2 -m 64 -machine virt -nographic \ -kernel arch/riscv/boot/loader \ -drive file=rootfs.ext2,format=raw,id=hd0 \ -device virtio-blk-device,drive=hd0 Contains contributions from Damien Le Moal . Signed-off-by: Christoph Hellwig Reviewed-by: Anup Patel [paul.walmsley@sifive.com: updated to apply; add CONFIG_MMU guards around PCI_IOBASE definition to fix build issues; fixed checkpatch issues; move the PCI_IO_* and VMEMMAP address space macros along with the others; resolve sparse warning] Signed-off-by: Paul Walmsley